Path Traversal in Microsoft Windows
CVE-2026-39844
NiceGUI is a Python-based UI framework. Prior to 3.10.0, Since PurePosixPath only recognizes forward slashes (/) as path separators, an attacker can bypass this sanitization on Windows by using backslashes (\) in the upload filename. Appli…
Vulnerability class: Path Traversal (Directory Traversal)
EPSS: 0.004 (29.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N.
Affected products
- Microsoft Windows
- Zauberzeug Nicegui — versions < 3.10.0
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-39844?
- CVE-2026-39844 is a medium-severity vulnerability in Microsoft Windows, classified under Path Traversal. CVSS score: 5.9/10. Published 2026-04-08.
- How severe is CVE-2026-39844?
- Medium severity. CVSS v3 base score is 5.9 out of 10.